When the puppet cast of an '90s children's TV show called the Happytime Gang are brutally murdered one by one, a disgraced LAPD detective-turned-private eye puppet (Bill Barretta) takes on the case with the help of his ex-partner (Melissa McCarthy).

The somewhat taboo idea of taking something that's childlike and infusing it with adult humour isn't particularly new, no matter how much the advertising for 'The Happytime Murders' might have you think.

'South Park' did it, 'Drawn Together' did it, and arguably, 'Who Framed Roger Rabbit' started it all off and even blended the live-action elements together. So, really, from the get-go, 'The Happytime Murders' is on the back foot in terms of originality, and it doesn't end there.

The story is your garden variety detective noir, with a disgraced detective-turned-PI who's hired by a femme fatale in an unrelated matter that may or may not have something to do with a wider case forces him to reunite with the police department he's been ejected from and a partner he's been estranged from. 'Double Indemnity', 'Basic Instinct', 'Chinatown', it's all been done - the only thing 'The Happytime Murders' has going for it is that there's now puppet jokes running through it, and the novelty runs out pretty quickly.

Fuzzy puppet rabbits are sexual deviants, everyone makes sock jokes, puppets ejaculate silly-string when they orgasm, and there's even a major plot arc that hinges on female pubic hair. The sad thing is that 'The Happytime Murders' is trying so painfully to be edgy, so desperately to pervert the normal reaction to puppetry, that the humour falls flat on its velvet face. The jokes are made with all the subtlety of a fart in a bathtub and while the broad humour that 'The Happytime Murders' aims for isn't supposed to be subtle, this is on another level entirely. It tries so hard that it's almost embarrassing to witness.

The human cast, which includes Melissa McCarthy, Maya Rudolph, Elizabeth Banks and Joel McHale, don't particularly fare much better and essentially prove that the problem isn't with making puppets funny - it's that the script itself isn't funny either. Still, they're all trying their best to make it work and that's really the one thing that 'The Happytime Murders' can't be faulted on - a lack of effort by all concerned. Both director Brian Henson and the cast and performers are all doing their best, but there just isn't enough here to make it work and when you consider that 'The Happytime Murders' is at least ten years in the making, you'd think that they would have come back with something better.

'The Happytime Murders' feels like a wasted opportunity to make something really funny, or at the very least, something as subversive and satirical as the initial premise suggests. There are a few moments that are more shocking than funny, and the gross-out humour might spur a laugh or two here and there, but 'The Happytime Murders' just doesn't have enough going for it to be anything other than a failed experiment that could have been so much more.